Structural component and a method and machine for its manufacture

ABSTRACT

A method for manufacturing an elongated, box-like structural component comprising two mutually opposing side-members (1, 2) which define a cavity therebetween. The mutually opposing surfaces of the side-members present longitudinally extending grooves into which projections on distance pieces (3) located between the members engage. In the process of manufacturing the structural component pairs of boards or the like are advanced in spaced relationship in the longitudinal direction of the boards into a receiving station (7) with the grooved inner surfaces of the boards facing one another, the distance pieces (3) being placing between the boards as they enter the station (7). As the boards leave the station, they are pressed towards one another in a manner to bring the projections on the distance pieces (3) into engagement with the grooves on the inwardly facing surfaces of the boards. The invention also relates to a machine for use when carrying out the method, and to a structural component manufactured in accordance with the method.

In the art of building materials there is known a structural componentintended for wall structures which comprises an elongated box-likeelement having two mutually opposing side members which define a cavitytherebetween and the mutually facing inner surfaces of which presentlongitudinally extending grooves, and between which side members thereare located distance pieces having projections which engage in thegrooves.

In the manufacture of structural components of this kind it has beennecessary to employ hitherto methods which can be described more or lessas handicraft methods, which has made manufacture a slow and expensiveprocess.

One object of the present invention is to provide a method and a machinefor enabling the continuous manufacture of such structural components ina rational fashion.

The method and machine according to the invention can also be utilizedto manufacture a further development of the aforesaid structuralcomponent intended for wall structures, this modified structuralcomponent being suitable for use as a self-supporting floor componentand the like.

Consequently, a further object of the invention is to provide astructural component of the aforedescribed kind which is capable ofbeing used as a component in floor structures.

One advantage afforded by a structural component of the aforesaid kindis that the component obtains and retains its final form immediately theplate-like distance pieces are brought into engagement with the sidemembers of the component. This advantage is utilized in the method ofthe manufacture according to the invention, which enables such astructural component to be produced continuously in indefinite lengths,and then cut into required lengths.

The method according to the invention for manufacturing a structuralcomponent of the aforesaid kind is particularly characterized byadvancing longitudinally to a receiving station pairs of mutually spacedboards or the like which are operative in forming the side members ofthe component and which have grooves provided in the mutually facingsurfaces thereof; by placing and supporting the plate-like distancepieces on an endless belt extending in the longitudinal direction of theboards and moving said belt at a speed corresponding to the speed atwhich said boards are advanced; by bringing the distance pieces betweenthe boards of an incoming pair of boards; and by pressing the boardstowards one another as they leave the station, so as to bring theprojections on the distance pieces into engagement with the grooves inthe inwardly facing surfaces of the boards.

In this regard the distance pieces are preferably supported bysupporting means mounted on the belt and projecting in between theboards.

When manufacturing insulated structural components, insulating foam canbe ejected continuously into the aforesaid cavity as the buildingstructural component leaves the station for fitting of the aforesaiddistance pieces, these distance pieces separating the cavity into aplurality of separate compartments, wherewith the normally open sides ofthe cavity are held closed with the aid of belts or bands which extendalong and are pressed against the edge surfaces of the side members ofthe component under construction.

The particular characteristic features of a machine for manufacturing astructural component when using this method are set forth in thefollowing claims

The aforementioned further development of the structural componentdescribed in the introduction for use as a self-supporting floorcomponent or the like, where the side members of the structuralcomponent respectively form the top and bottom surfaces of the floorstructure, is characterized in that each of the side members is providedwith an upwardly facing groove which extends along one longitudinal sideedge of the structural component, and with a

correspondingly downwardly depending tongue along the other longitudinalside edge of the component. A tongue and groove joint of thisconstruction, formed at right angles to the plane of the boards, enablesthe floor components to be joined together readily and simply and alsoprovides a more rigid floor of greater bearing capacity than thatobtained when joining the boards together through the agency ofconventional tongue and groove joints located in the plane of theboards.

The floor component is also suitably filled with insulating foam, andcan be further reinforced by introducing stiffeners between theplate-like distance pieces.

In accordance with one embodiment, which facilitates, inter alia, layingof the floor components, the top side member is displaced laterally inrelation to the bottom side member.

The invention will now be described in more detail with reference to theaccompanying drawings, in which

FIG. 1 illustrates in perspective the manner of laying a floor componentaccording to the invention;

FIG. 2 is an end view corresponding to FIG. 1;

FIG. 3 is a corresponding end view illustrating a modified embodiment ofthe floor component; and

FIG. 4 illustrates schematically the principle construction of a machinefor producing box-like structural components.

As illustrated in FIGS. 1 and 2, a floor component according to theinvention comprises a top side-member 1 and a bottom side-member 2, eachof which comprises in this example two mutually joined boards. In amanner known per se each of the side-members 1 and 2 has extending alongthe inwardly facing surfaces thereof a plurality of longitudinalgrooves, and the boards are mutually joined together in a known mannerby distance pieces 3 which engage in the grooves and divide the cavitydefined by said side members into separate compartments. The structuralcomponent can be stiffened with the aid of braces 4 or like elementsarranged to join mutually adjacent distance pieces 3. The cavity definedby the side members and divided into separate compartments by thedistance pieces is suitably filled with insulating foam.

The braces 4 may be replaced with other devices, for example withwood-fibre strips which extend in the longitudinal direction of theboards and engage opposing grooves therein. These strips areconveniently perforated, to enable foam to fill the cavity between theboards completely. The use of stiffening strips arranged in theaforesaid manner greatly enhances the supporting capacity of the floorstructure.

A floor component constructed in this way is extremely rigid, due interalia to the distance pieces 3, which are suitably spaced apart atdistances of about 30 cm. The braces 4, or the alternative stiffeningstrips, also contribute to the high degree of rigidity of the floorcomponent, as does also the foam insulation when present. In order toimprove the bearing capacity of a floor constructed from floorcomponents according to the invention still further, however, mutuallyadjacent components are joined together by means of a novel tongue andgroove joint.

Conventional tongue and groove joints include a groove and correspondingtongue which both extends in the plane of the associated boards. Inorder to improve the joint between mutually adjacent floor component inthe illustrated application, however, the tongue and groove joint iseffected by means of tongues and grooves which form angles ofsubstantially 90° with the plane of associated boards. To this end, agroove is provided along each of the side members 1 and 2 on one side ofthe structural member, said grooves both facing in mutually the samedirection, while mutually oppositely directed tongues are provided alongthe other side of the structural member. This enables one floorcomponent according to the invention to be readily hooked firmly to anadjacent floor component, in the manner illustrated, thereby stiffeningthe floor structure as a whole and eliminating the possible presence ofseasoning cracks between the floor components. This together with thelatching effect on the wood in the side-members 1 and 2 afforded by thedistance pieces 3 enables a floor to be constructed from structuralcomponents according to the invention with which there is a minimum riskof crack formation or movements between the individual boards.

In order to further improve the joint between mutually adjacent floorcomponents and the rigidity of the transition region, an elongatedstrip-like element 5, for example a wood-fibre strip, can be inserted inslots 6 in the side edges of the distance pieces 3, as illustrated inFIGS. 1 and 2. In order to improve the stiffening effect of thestrip-like elements 5 and to facilitate laying of the floor components,the top and bottom side members 1 and 2 of the illustrated embodimentare displaced laterally in relation to one another. This is not anessential feature of the invention, however, and elements of purelyelongated rectangular cross-section can be manufactured. The use ofinclined components, however, improves among other things the sealbetween mutually adjacent, foam-filled components.

FIG. 3 illustrates an alternative method of producing a stiffening jointbetween mutually adjacent floor components this alternative methodsimplifying manufacture of the floor components and the laying thereof.Instead of the obliquely fitted strip-like element of FIGS. 1 and 2there is used in the FIG. 3 embodiment horizontal, suitably slightlywedge-shaped elements 20, which can be inserted from one end of eachfloor component into a horizontal groove 21 extending along onelongitudinal side of the floor component. The groove 21 has awedge-shaped cross-section corresponding to that of the strip-likeelement 20, but slightly larger dimensions than said element. Thereference 22 identifies a wedge-shaped groove which corresponds to thestrip-like element 20 and which extends along the other longitudinalside of each floor component, and the reference 23 identifies aplurality of transverse holes disposed along the length of said element.

In this embodiment mutually adjacent floor components can be joinedtogether by pressing the strip-like element carried by one floorcomponent into a corresponding groove 22 located in an adjacent floorcomponent, with the aid of a lever or some other suitable tool. Thestrip-like element 20 will therewith tightly conform to the definingsurfaces of the grooves 21 and 22.

Because the boards are effectively held together in correct positionsrelative to one another with the aid of the distance pieces 3, astructural component according to the invention can be produced in acontinuous process. A method and a machine herefor will now be describedwith reference to FIG. 4. The machine illustrated schematically thereinis intended for the manufacture of structural components of purelyelongated rectangular cross-section, for example for wall structures,but can be readily modified for manufacturing the structural componentsillustrated in FIGS. 1 and 2.

When practising the embodiment of the invention illustrated in FIG. 4,the two side-members 1 and 2 of the structural component are guided intoa station 7 by means of rollers 8, which are driven by a motor 9.Distance pieces 3 are positioned between the incoming pair ofside-members 1 and 2 in the station 7, with the aid of an endless belt10 having supports 11 for supporting the distance pieces 3, which arefed from a magazine 12. When braces 4 are required, these braces areplaced between the distance elements 3 in the station 7. The meansrequired for positioning the distance pieces 3 and the braces 4 can beof any desired construction. The only necessity in this respect is toensure that the distance pieces 3 are held correctly in position betweenthe side-members 1 and 2 when the side-members are pressed towards oneanother by means of the illustrated outer rollers 13, as theside-members leave the station 7.

The projections on the distance pieces 3 intended for engagement withrespective grooves in the side-members 1 and 2 are coated with glueprior to positioning the distance pieces between the side-members, whichare firmly fixed relative to one another immediately they are pressedinto engagement with the distance pieces, inter alia as a result of thefriction between projections and grooves. Among other things it is thiswhich enables the structural component to be manufactured in acontinuous process, since said component need not be held under pressurein a stationary press device.

The individual boards forming the side-members can be joined end to endwith one another as they are held fixed relative to one another by thetongue and groove joint between the two boards of each side-member, andby the distance pieces 3. Because the structural component according tothe invention can be manufactured in a continuous running length,unnecessary wastage is avoided both when manufacturing the structuralcomponent, since whole board lengths can be used, and in the latter useof said component, since components of suitable lengths for the use inquestion can be pre-cut from a single long length. The design of thestructural component also enables it to be readily filled withinsulating foam in conjunction with the manufacture of the component. Tothis end there is arranged a foam-filling nozzle 14 at that position inthe machine where the side-members 1 and 2 are pressed into engagementwith the distance pieces 3. Foaming of the insulating substance takesplace in the cavity presented between the side-members 1 and 2 anddivided into separate compartments by the distance pieces 3. Thepressure in the cavity increases considerably during foaming of theinsulation, and is taken up laterally by the rollers 13. The normallyopen sides of the structural component are held closed along that partof the machine at which foaming takes place, by means of an upper and alower endless steel belt 15 and 16, which accompanies the movement ofthe structural component and is pressed sealingly against the side edgesof the side-members 1 and 2 thereof. To this end there are used on therear sides of the belts 15 and 16 counter-pressure devices (not shown)having a low-friction slide surface facing towards respective belts.

The ease with which the structural component can be filled with foam isdue to the distance pieces 3, which function as throttles. Without thepresence of sealing distance pieces, the foam mass would be pressed outof the cavity in a direction towards the station 7. The distance pieces3, however, form together with the belts 15 and 16 and the side-members1 and 2 closed chambers which enclose the foam.

The fact that the structural component can be filled with foam duringthe process of manufacturing the component affords several advantages,among which can be included a significantly more effective and morereadily controlled filling of the component with foam and more rationalconstruction, since it is no longer necessary to fill the structuralcomponent with foam insulation in a separate working stage on theworking site. In addition hereto, a foam-filled structural componentaccording to the invention is completely straight, and will notsubsequently change shape as a result, inter alia, of the barrier actionof the foam.

The aforedescribed machine can be modified in various respects withinthe scope of the following claims, while retaining the advantages ofcontinuous and rational manufacture of a structural component, withsimultaneous filling of the component with foam insulation. Thisapplies, for example, to both the station 7 for mounting the distancepieces, and the arrangement for sealing the aforesaid cavity whenfilling the compartmental cavities between the distance pieces withfoam.

We claim:
 1. A method for manufacturing an elongated, box-likestructural component, comprising two mutually opposing side-memberswhich define a cavity therebetween and the mutually inner surfaces ofwhich present longitudinally extending grooves, and between whichside-members there are located distance pieces having projections whichengage in respective grooves, said method comprising advancinglongitudinally to a station pairs of mutually spaced boards or the likeserving to form the side-members of the structural component and havinggrooves provided in the mutually facing surfaces thereof, the methodbeing characterized by the further steps of placing and supporting theplate-like distance pieces (3) on an endless belt (10) extending in thelongitudinal direction of the boards, such as to position the distancepieces between said boards in said station, said belt (10) being movedat a speed corresponding to the speed at which said boards are advanced;and by pressing the boards towards one another as they leave thestation, so as to bring the projections of the distance pieces intoengagement with respective grooves in the inwardly facing surfaces ofthe boards.
 2. A method according to claim 1, characterized bysupporting the distance pieces on the belt with the aid of support meansprojecting in between the boards.
 3. A method according to claim 1 orclaim 2, characterized by placing the distance pieces between the boardsfrom a magazine located on the opposite side of the pair of boards inrelation to said belt.
 4. A machine for manufacturing an elongated,box-like structural component comprising two mutually opposingside-members (1,2) which define a cavity therebetween and the mutuallyfacing inner surfaces of which present longitudinally extending grooves,and between which side-members there are located distance pieces (3)having projections which engage in respective grooves, and which machinecomprises means (8,9) for advancing longitudinally to a station (7)pairs of mutually spaced boards or the like serving to form theside-members (1,2) of the structural component with the grooved surfacesof the boards facing one another, said station incorporating means forpositioning the distance pieces between a pair of incoming boards,characterized in that said station (7) includes a magazine (12) forstoring distance pieces (3), and an endless belt (10) which moves in thelongitudinal direction of the pair of boards and which provides supportfor distance pieces fed from the magazine, said belt (10) being drivenat a speed corresponding to the speed at which the boards are advanced,and means (13) for pressing the boards towards one another in a mannerto cause the projections on the distance pieces (3) to engage inrespective grooves on the inwardly facing surfaces of the boards as thepair of boards leaves said station.
 5. A machine according to claim 4,characterized in that the belt (10) is provided with support means (11)intended for supporting the distance pieces (3) and extending in betweenthe boards.
 6. A machine according to claim 4 or claim 5, characterizedin that the magazine (12) is located on the opposite side of the pair ofboards relative to the belt (10).
 7. A machine according to any one ofclaims 4 or 5, intended for manufacturing insulated structuralcomponents characterized in that the machine further includes at leastone nozzle (14) for injecting insulating foam into the cavity defined bythe side-members, said cavity being divided into separate compartmentsby the distance pieces, and belts or bands (15,16) which are intended toseal-off the normally open sides of the cavity and which accompany themovement of the structural component and are pressed sealingly againstthe edges of the side-members (1,2) thereof.
 8. An elongated, box-likestructural component intended for use as a self-supporting floorcomponent or the like comprising two mutually opposing side-members(1,2) which includes a top side member and a bottom side member anddefine a cavity therebetween and the mutually facing inner surfaces ofwhich present longitudinally extending grooves, and between whichside-members there are located distance pieces (3) having projectionswhich engage respective grooves, said side-members (1,2) being intendedto form the top and the bottom surfaces respectively of the floorstructure, characterized in that each of said side-members (1,2) isprovided with an upwardly facing groove along one longitudinal side edgeof the structural component, and with a corresponding, downwardlydepending tongue along the other longitudinal side edge of saidcomponent.
 9. A structural component according to claim 8, characterizedin that stiffening means (4) are arranged between the distance pieces(3).
 10. A structural component according to any one of claims 8 or 9,charaterized in that the top side member (1) is displaced laterally inrelation to the bottom side member (2).